Chemistry Q59 – JEE-MAIN 2025

Home Chemistry Periodicity & ElementsQuestion #530

Given below are two statements : Statement (I) : The metallic radius of Al is less than that of Ga. Statement (II) : The ionic radius of

A l^{3 +}

is less than that of

G a^{3 +}

. In the light of the above statements, choose the most appropriate answer from the options given below :

Clue 1 of 3: Periodic Trends

Recall the general trend of atomic/ionic radii down a group and factors that can cause deviations.

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● Video Walkthrough

Step 1: Analyze Statement (I) - Metallic Radii✦ Active

Generally, atomic radii increase down a group. However, Gallium (Ga) follows the d-block elements. The poor shielding effect of the 3d electrons in Ga causes an increase in effective nuclear charge, leading to d-block contraction. This results in the metallic radius of Ga (135 pm) being slightly smaller than that of Al (143 pm).

Therefore, Statement (I) "The metallic radius of Al is less than that of Ga" is incorrect, as Al's radius is greater than Ga's.

Step 2: Analyze Statement (II) - Ionic Radii○ Expand

For ions of the same charge in the same group, ionic radius generally increases down the group due to the addition of new electron shells. $A l^{3 +}$ is in Period 3 and $G a^{3 +}$ is in Period 4. The ionic radius of $A l^{3 +}$ (53.5 pm) is smaller than that of $G a^{3 +}$ (62 pm).

Therefore, Statement (II) "The ionic radius of $A l^{3 +}$ is less than that of $G a^{3 +}$ " is correct.

Step 3: Combine Conclusions○ Expand

Statement (I) is incorrect, and Statement (II) is correct. This corresponds to option 4.

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Chemistry Question 59 – JEE-MAIN 2025

Clue 1 of 3: Periodic Trends

🧠 Full Solution Path